bug#35443: 27.0.50; Gnus (nnimap) shows "ghost" messages in summary buffer

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Ulrich Mueller <ulm@gentoo.org> writes:

>>>>>> On Sat, 27 Apr 2019, Eric Abrahamsen wrote:
>
>> Huh. Can you show us the value of gnus-newsgroup-data and
>> gnus-newsgroup-headers in this group?
>
> See below, for the current group, whose summary buffer shows your
> article and a dummy article.
>
>> Does the dummy article always show up?
>
> It always shows up when new articles have been fetched. It doesn't
> show up when entering a group that doesn't have new mail (i.e., if a
> group previously had a dummy article, it will be gone when reentering
> that group).
>
>> Only in this group?
>
> All groups for that particular IMAP server. 
>
>> Is this a newly-added IMAP server, and did it display this problem
>> right from the beginning?
>
> AFAICS, the problem appeared after dovecot on the server side was
> upgraded from version 2.2.34 to 2.3.5.1. But I see it only with Gnus.
> I don't have any issues with Mozilla Thunderbird (on GNU/Linux) nor with
> K-9 Mail (on Android/Linux).

Thanks, this should be enough to make some progress in tracking the
problem down. Give me a couple of days...